1. Field of the Invention
This invention relates to thrust bearings and more particularly to diamond bearing segments with cooling and lubrication channels.
2. Description of the Related Art
Diamond bearings have found application in oil drilling and other environments demanding high load carrying ability under extreme wear conditions. As used herein, the term diamond includes synthetic diamond such as polycrystalline diamond. When used as a thrust bearing, a pair of load carrying structures containing diamond pads, also called inserts, are arranged in opposition to bear against one another. One such common arrangement for a thrust bearing is shown in FIG. 1, where a load ring 1 has a number of individual diamond bearing inserts 2 disposed concentrically therein. The thrust load is carried by the bearing surface 3 of each insert.
The load carrying capacity of such a bearing is limited by the frictional heat build up in the diamond bearing inserts. The heat buildup is related to the unit area loading of the bearing insert and to the availability of cooling mechanisms to remove the heat generated. A thermal limit is eventually reached beyond which the inserts begin to degrade and ultimately may disintegrate. Replacement of any bearing in a downhole environment is undesirable due to the expense and downtime involved in pulling and repairing such equipment.
The methods and apparatus of the present invention overcome the foregoing disadvantages of the prior art by providing a novel bearing having an increased surface area for lowering the unit loading and integral flow channels for cooling the bearing.